GB1599170A

GB1599170A - Construction members

Info

Publication number: GB1599170A
Application number: GB5437577A
Authority: GB
Original assignee: QUARIO S
Current assignee: QUARIO S
Priority date: 1976-12-30
Filing date: 1977-12-30
Publication date: 1981-09-30
Also published as: FR2376177B3; FR2376177A1; NL7714584A; DE2758389A1

Description

(54) IMPROVEMENTS IN OR RELATING TO CONSTRUCTION MEMBERS (71) I, SERGIO QUARIO, an Italian subject, of Piazza Unita d'Italia No. 54, SARONNO (Varese), Italy, do hereby declare the invention, for which I pray that a patent may be granted to me and the method by which it is to be performed to be particularly described in and by the following statement: This invention relates to construction members and, more particularly to construction members which can be prepared from material in the liquid or semi-liquid state, and then hardened in moulds to provide members of sufficient tensile and compressive strength to be used in manufacturing buildings or parts of buildings.

Further characteristics, such as heat and electrical insulation and resistance to fire are highly desirable in construction members.

Up to the present time, all known materials possessing the required characteristics of workability, mouldability or castability and strength have belonged to the family of materials composed of cement containing inert filler materials, such as concrete, reinforced concrete, light concrete and the like. However, these materials, also have various properties which can seriously limit their use in certain construction sectors.

Firstly, cement-based materials, with or without filler materials or reinforcements such as iron reinforcements, are poor heat insulators and therefore create serious air conditioning problems in buildings in very hot or very cold regions.

Furthermore, these materials are characterised by a very high specific gravity, exceeding approximately twice the specific gravity of distilled water, which considerably complicates their handling, conveying and installation in the case of large prefabricated members such as beams, roofing vaults or the like.

Finally, cement-based materials have certain very poor mechanical characteristics, such as tensile strength, which affects their use in constructing building members which are subjected to high mechanical stresses.

These disadvantageous characteristics mean that such materials ae generally used in combination with iron elements which substantially improve their very low tensile strength and consequently their flexural strength, and recently attempts have been made to use them in combination with other materials having complementary characteristics, for example, much lighter materials which have good insulating characteristics, such as clay, schists, slag and expanded synthetic materials, to remedy their deficiency in this latter characteristic.

These complementary materials, in particular expanded synthetic materials, which offer good insulation, can be cast into moulds and are impermeable, but possess very good mechanical characteristics.

The present invention consists in a process for preparing an expanded, heat-insulating, fire-resisting, construction member, comprising preparing a mixture of liquid resol phenolic resin, filler material and hardener, said filler material being present in an amount up to three times the weight of the resol resin and said hardener being present in an amount of 1 6% by weight of the resol resin, placing the resulting mixture in the liquid state in a mould, heating the mould to effect controlled expansion and hardening of the resol resin, and removing the hardened casting from the mould.

The filler materials, which may include light weight fillers, are added to the resin up to 300%, by weight, while still maintaining a product of very high mechanical characteristics, and always far superior comparatively to those of concrete. Also, inserts or reinforcements, including metal reinforcements, may be incorporated in the construction member and one manner in which the adhesion coefficient between the resin and metal may be greatly increased is described hereinafter.

In one embodiment of the invention, the process comprises mixing in a turbo mixer about 100 parts by weight of a resol phenolic resin with 5 parts by weight of a hardener (94% to 96% of resin by weight plus 4 to 6% of hardener by weight), and mixing the mixture for a time of 30 to 50 seconds. The dense liquid thus obtained is cast into a mould, which is then closed leaving only a few vent holes open. The mould must be completely filled with the resin once it has expanded and hardened. In this embodiment the total fillable volume of the mould, Vs, is greater than the volume of the cast liquid or mixture (resin), Vm, the ratio Vs:Vm being in the range 1 to 2, and the mould must be able to support or withstand an internal pressure of the order of 1 to 2 Kg. per cm2.

When the liquid resin has been poured into the mould as heretofore defined, the mould is then placed in an environment heated at 75 to 950C and remains there for 15 to 25 minutes.

The casting may then be removed from the mould and returned to the environment heated at 45 to 90"C for a further 40 to 80 minutes (normalising time).

The final cast product or member obtained has a density from 0.84 to 0.97 gm/c.c., an ultimate tensile stress of the order of 179 kg/cm2, and an ultimate compressive stress of the order of 400 kg/cm2. These values may vary slightly according to the type of resin and the normalising and hardening times. The member is fire resistant, and has high heat insulation.

A test consisting of exposing a half cylinder of the material of the member with a diameter of 7 cm to the action of a Bunsen burner placed about 3 cm from the base of a cavity provided in the centre of the curved side, and of depth 2.5 cm, showed that the temperature measured at the exterior of the flat side increased from 20"C to 102.5"C in a time of 76 minutes, this latter temperature then remaining substantially constant (see Figure 1).

The filler material either substantially reduces the specific gravity of the final product or reduces its cost without substantially influencing the mechanical and other physicalchemical characteristics, which always remain comparatively high relative to the corresponding characteristics of concrete.

Thus, for example, 100 parts by weight of resol phenolic resin in the liquid state are mixed in a turbo mixer with up to 300 parts by weight of filler material which may be ventilated quartz, small hollow glass beads, expanded polystyrene beads or the like. A first mixture is then obtained comprising 25 to 40% of resin by weight and 60 to 75% of inert material by weight. After mixing in the turbomixer, the dense liquid obtained may be kept for up to 40 hours without any substantial changes occurring either to the resin or to the dispersion of the filler material in the resin. Then, immediately before casting, 5 parts by weight of hardener are fed into the turbomixer for each 100 parts by weight of resin present in the first mixture, so that in fact 1.25% to 2% by weight of hardener are fed to the first mixture in the turbomixer. After a mixing time of about 20 to 50 seconds, the liquid is cast into a mould.

The mould is of the same type as described above and is able to support the same internal pressure. After a period of 5 to 9 minutes the mould is placed in a suitable heated environment, such as an oven, where the temperature of the mould and its contents is raised to 75 to 95"C for a period of 15 to 25 minutes.

The cast member is then removed from the mould and, if good normalisation of its chemical, physical and mechanical characteristics is required, it must be returned to the oven for a further 45 to 90 minutes at a temperature of 45 to 900C. During the first mixing stage with the inert filler material, further additives may be added such as sorbitor and zinc stearate.

These additives improve the mechanical strength characteristics of the final product when added in a quantity of 0.5% or more by weight relative to the weight of the resin contained in the mixture. The product obtained from the aforesaid embodiment of the process has a specific gravity from 0.3 to about 1, and a mechanical strength substantially five times greater than the corresponding strength of concrete. It has very high thermal insulation and excellent resistance to flame action (of the same order as already stated). The addition of the aforesaid additives produces the following changes in the basic characteristics of the final product: a) the addition of sorbitol in a quantity of 4.5% to 12.5% of the final product by weight leads to an increase in the specific gravity of 19% to 22%, and an increase in the compressive strength of greater than 50sic; b) the addition of zinc stearate in a quantity of 0.5% to 1% of the final product by weight leads to an increase in the specific gravity of 2% to 4%, an increase in the compressive strength of 8 to 10%, and a reduction in the flexural strength (and comparatively the tensile strength) of 40 to 50%.

Having regard to the improvements accompanying the use of the above mentioned additives, a study has been made of two different types of member obtainable by the aforesaid embodiment of the process. their formulations being slightly different in order to produce members for different uses. Two formulations were studied, for the construction of: 1. beams, the product being provided with good flexural and tensile strength, but without special consideration being given to its specific gravity; 2. slabs, the product being provided with good compressive strength (exceeding that of concrete) and low specific gravity, but without special consideration being given to its tensile strength, If it is required to embed iron reinforcements in the members, it is preferable to coat the reinforcements with epoxy paint in order greatly to increase their adhesion to the material.

The above embodiments provide materials for construction members which can be used with reinforcements such as iron, and which possess a mechanical strength which is comparatively much higher than that of concrete (with special reference to tensile strength), and with a specific gravity which is much lower than or at the most close to the specific gravity of distilled water. Further, the material can be used to produce members which are easily glued together on site to provide a mechanical strength which is at least equal to that of the material itself. Also, the material produced may have a compressive and tensile strength substantially equal to five times the compressive and tensile strength of traditional concrete, including light concrete. This material, of very high mechanical strength, and which has been cast in moulds, has very high heat insulation, is of comparatively low cost, and has a surprising resistance to fire.

The moulding operations described above are performed without using traditional blowing additives, such as fluorinated hydrocarbons marked under the Registered Trade Mark of Freon, or Freon-based substances, and with the addition of only a very small quantity of hardener, comparatively much less (1/6 or 1/7) than that used in known processes.

In the majority of practical cases, it has been found that the superior mechanical characteristics of the members obtained by the above mentioned embodiments of the process exceed actual requirements. For this and for economical reasons, it it therefore advisable to produce less expensive members, even though they may be comparatively weaker. According to an alternative embodiment of the process, this is obtained by limiting the quantity of resin and increasing the fillers, and including in the mixture small quantities of blowing agents such as liquid Freon. The amount of blowing agent added is 2 to 4% of the mixture by weight. The addition of these small quantities of blowing agent, these quantities being much less than the percentages added to known expanded products, creates further problems with regard to small scale manufacture of the members. This small scale manufacture is obtained by replacing a heated environment such as an oven, in which hardening occurs, with a hot plate press, preferably a multiple plate press each of which comprises at least five compartments. In this case the addition of the blowing agent, even when less than 3% of the mixture by weight, generally does not leave sufficient time (at least 30 minutes) for all the compartments of the press to be served. Furthermore, the use of this type of press is greatly limited by another problem which arises in the first mentioned embodiments of the process, namely that the normal cold hardening time of the mixture, known as the pot life, and equal to 3 to 5 minutes, is insufficient and must be increased at least to 25 to 30 minutes.

In the present alternative embodiment, small quantities, for example of the order of 3%, of a normal blowing agent are added, and the formulation and succession of mechanical operations concerned in the process are altered so as to avoid the aforesaid drawbacks.

Thus the filler material of the mix contains a substantial amount of hollow glass beads.

When present to an extent of not less than 3% by weight, and preferably 3 to 9% by weight, these hollow glass beads have demonstrated the capacity to considerably extend the pot life, especially if used with silica as a mineral filler. Furthermore, in addition to comprising the aforesaid proportion of hollow glass beads in its formulation, this alternative embodiment provides for very small quantities of alpha copper modified phthalocyanine, as defined by the following formula, or an equivalent product, to be added to the blowing agent.

The alpha copper modified phthalocyanine is not used as a blowing agent, but, in combination with a normal blowing agent, has shown surprising characteristics which modify its behaviour. In this respect, if the blowing agent is used alone in the mixture, it acts in a relatively short time so that the product becomes expelled from the mould. This undesirable behaviour may be avoided by preventing the mass from rising by means of mechanical agitation. However, this operation has the disadvantage of favouring evaporation of the blowing agent, and preventing its action from continuing after the mechanical agitation.

The addition of a very small quantity of the phthalocyanine, of 0.02 to 0.1% by weight of the expanded product, avoids this drawback and enables the expansion of the mass to be delayed, until the required moment, by mechanical agitation.

The alternative embodiment relates to formulations as indicated in Table 1.

TABLE 1 COMPONENT % by weight Resin 20-35 Mineral fillers 70-50 Hollow glass beads 3-9 Hardener 5-8 blowing agent 2-4 Phthalocyanine 0.02-0.1 which are handled and prepared as follows.

The components of the mixture are previously made up into premixes in two separate groups in two different tanks, one group containing all the hardener (group I).

The said two mixes, indicated hereinafter simply by -R- and -I-, have the formulations given in the following tables in order to provide them with the same viscosity for more rapid and homogeneous final mixing.

TABLE 2 Mix -R- Average Resin 41 - 45% 43% Fillers 50 - 53% 52% Hollow glass beads 4 - 6% 5% TABLE 3 Mix -I Fillers 48 - 52% 50% Hollow glass beads 4 - 6% 5% blowing agent 11 - 15% 13% Hardener 30 - 34% 32% Modified alpha phthalocyanine 0.08 - 0.4% 0.24% With the above formulation, the proportion of mixed R to mixed I by weight is about 3:1, but the similar viscosity of the two mixes ensures easy correct final mixing. The overall formulation obtained when the two mixes are mixed together is that given in Table 1.

This may be verified if necessary, assuming a weight ratio R:I = 3, as follows: 3 Resin 43 . 4 = 32.25 Fillers 52 . 3 + 50 4 = 51.5 Hollow glass beads 5.3+5 = 5 4 15 blowing agent 4 = 3.25 Hardener 32 = 8 Phthalocyanine 0.24 = 0.06 4 The two mixes R and I, in accordance with Tables 2 and 3 and based on Table 1, are prepared in sufficient mix quantities for about four hours of production.

About every 30 minutes, mix R should be treated with a turbo-mixer to prevent the heavier fillers from settling. The required quantities of mix R and mix I, in that order, are then taken and mixed together, and then cast into the moulds. Each mould is filled with a sufficient quantity of mixture to obtain the required density of the construction member.

For example, to obtain a density of 0.4 kg/dm3, each mould would be filled to approximately 40%, or where Vm is the volume of mixture cast into the mould and Vs is the total mould volume the ratio Vm:Vs would be in the range 1 to 2.

With the moulds, still open and already filled to the required extend, they are subjected to mechanical agitation (which may be repeated), for example by means of a rake, to prevent premature unrequired blowing of the product and consequent spillage from the moulds. When the moulds are completely filled, they are closed and inserted into the compartments of the multiple plate press, the plates of which are heated to a temperature of the order of 80-90"C for a time of 10 to 30 minutes.

After the controlled expansion and hardening in the press, the mouldings are removed and fed to the curing stage.

In order that the invention may be more readily understood, reference will now be made to the accompanying drawings, in which: Figure I is a diagram which illustrates the heat insulation characteristics of material made according to the invention, and shows the design of a test piece to actual scale, Figure 2 is a perspective view of a closed mould.

Figure 3 is a partlal perspective view of the mould when open.

Figure 4 is an enlarged sectional view of the closed mould on the line IV-IV of Figure 2; and Figure 5 is a perspective view of the cast constructed member.

Figures 2 to 4 show a mould suitable for moulding a H beam, and constituted by a base 1 provided at its periphery with apertures 2 into which the outer appendices 3 of the side walls 4 and end walls 5 are inserted.

The side and end walls are connected together by hooks 6 disposed in proximity to their perimetral edges.

The side and end walls comprise semi-cylindrical cavities 7 in their upper edges, to act as vents.

A cover 8 is fixed firmly on the top by hooks 9. The beam formed is indicated by 10.

Example 1 100 parts of a resol phenolic resin, produced by the firm SHEBY of 119 Route de Carrieres, 95-Begons, France, under the catalogue No. 76,009, were fed into a turbomixer together with 60 parts by weight of normal commercially available hollow glass beads. After a mixing time sufficient to disperse the hollow glass beads in the resin mass, the liquid paste obtained was able to be stored for a period not exceeding 40 hours without any changes occurring. Just before casting it into the mould, the mixture prepared in this manner was returned to a turbomixer and 5 parts of hardener marketed by SHEBY under the catalogue No. 76,058 were added for every 100 parts of resin. Mixing was carried out for 1.5 minutes, after which the product was cast into a closed mould of the metal form type with vents, which was able to resist an internal pressure of 2 kg/cm2 and had a volume of 1.5 times the volume of the mixture. After casting, the product was allowed to stand for a time of about 8 minutes and then inserted into an oven at 900C for 20 minutes, then removed and returned to the oven for a further 90 minutes.

The product obtained had a compressive strength of 134 kg/cm2 and a specific gravity of 0.463. Its head insulation and fire resistant characteristics were as described above with reference to Figure 1.

Example 2 In this test, 100 parts of resol phenolic resin (SHEBY 76.009) and 200 parts by weight of ventilated quartz were mixed in a turbomixer. 5 parts of hardener (SHEBY 76,058) were then added for every 100 parts of resin, and the mixture was rapidly mixed for 1.5 minutes.

It was then cast in the mould and allowed to stand for 8 minutes outside the oven, followed by baking at 900C for 20 minutes in the mould and a further 90 minutes out of the mould. A member was obtained with a specific gravity substantially equal to 1, and a compressive strength of 201 kg/cm2 (which was less than the previous values) for a very low cost (between a half and a third of the cost of the material of Example 1).

In this example, the mould volume was 1.9 times the mixture volume.

Example 3 This test relates to the manufacture of a panel using the proposed alternative embodiment of the process.

Mix R was prepared in a tank, and comprised Resin 19 kg (SHEBY 76,009) Silica 22 kg Hollow glass beads 2.175 kg.

and was homogenised by mixing in a turbo-mixer. Mix I was simultaneously prepared in a separate tank, and comprised Silica 7.5 kg Hollow glass beads 0.725 kg Blowing agent 2 kg Hardener 4.750 kg (SHEBY 76,058) Phthalocyanine 0.015 kg These two mixes are practically stable, but require occasional mixing to prevent sedimentation.

The two mixes were then mixed together for about 20 seconds, and then poured into a substantially flat mould of 3 x 1.20 x 0.04 metres (144 dm3), provided with normal vents.

After about 10 minutes, the mould was agitated mechanically with a small rake. After a further 15 minutes, the mould was placed between press plates heated to 90 C.

After 10 minutes the casting was extracted from the press and then cured.

The physical and mechanical characteristics of the casting were as follows: Weight 58.165 kg Density 0.404 kg/dm3 Tensile strength 56 kg/cm2 Compressive strength 148 kg/cm2 WHAT I CLAIM IS: 1. A process for preparing an expanded, heat-insulating, fire-resisting, construction member, comprising preparing a mixture of liquid resol phenolic resin, filler material and hardener, said filler material being present in an amount up to three times the weight of the resol resin and said hardener being present in an amount of 1 - 6% by weight of the resol resin, placing the resulting mixture in the liquid state in a mould, heating the mould to effect controlled expansion and hardening of the resol resin, and removing the hardened casting from the mould.

2. A process as claimed in claim 1, wherein said hardener is present in an amount of 4 to 6% by weight of the resol resin.

3. A process as claimed in claim 1 or 2, comprising the steps of: (a) mixing the filler material with the liquid resol resin, (b) adding the hardener to the mixture, (c) mixing the resulting mixture for 15 to 50 seconds, (d) casting the mixture obtained by step (c) in a closed mould which is provided with vents, which is capable of supporting an internal pressure of 2 Kg/cm2 and which has a volume of 1 to 2 times the volume of the mixture to be cast, (e) allowing the filled mould to stand at ambient temperature and pressure for 0.5 to 10 minutes, (f) heating said mould in an environment at 80 to 100"C for 15 to 25 minutes; (g) removing the hardened casting from the mould and heating the casting in an environment at 80 to 100"C for 45 to 90 minutes.

4. A process as claimed in claim 3, with the modification that the mixture obtained in step (c) is cast into a closed mould, the mould is then allowed to stand at ambient temperature and pressure for 12 to 48 hours, and the hardened casting is removed from the mould.

5. A process as claimed in claim 1, 2, 3 or 4, wherein the filler material comprises hollow glass beads and is added in a quantity of 0.5 to 0.7 times the resol resin quantity by weight.

6. A process as claimed in claim 1, 2, 3 or 4, wherein the filler material comprises expanded polystyrene beads, and is added in a quantity of 0.5 to 0.7 times the resol resin quantity by weight.

7. A process as claimed in claim 1, 2, 3 or 4, wherein the filler material comprises quartz powder, and is added in a quantity of 1.5 to 2.5 the resol resin quantity by weight.

8. A process as claimed in any one of the preceding claims, wherein zinc stearate is

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. Silica 7.5 kg Hollow glass beads 0.725 kg Blowing agent 2 kg Hardener 4.750 kg (SHEBY 76,058) Phthalocyanine 0.015 kg These two mixes are practically stable, but require occasional mixing to prevent sedimentation. The two mixes were then mixed together for about 20 seconds, and then poured into a substantially flat mould of 3 x 1.20 x 0.04 metres (144 dm3), provided with normal vents. After about 10 minutes, the mould was agitated mechanically with a small rake. After a further 15 minutes, the mould was placed between press plates heated to 90 C. After 10 minutes the casting was extracted from the press and then cured. The physical and mechanical characteristics of the casting were as follows: Weight 58.165 kg Density 0.404 kg/dm3 Tensile strength 56 kg/cm2 Compressive strength 148 kg/cm2 WHAT I CLAIM IS:

1. A process for preparing an expanded, heat-insulating, fire-resisting, construction member, comprising preparing a mixture of liquid resol phenolic resin, filler material and hardener, said filler material being present in an amount up to three times the weight of the resol resin and said hardener being present in an amount of 1 - 6% by weight of the resol resin, placing the resulting mixture in the liquid state in a mould, heating the mould to effect controlled expansion and hardening of the resol resin, and removing the hardened casting from the mould.

added to the mixture of filler material and liquid resol resin in the amount of 4.5 to 12.5% by weight of said mixture.

9. A process as claimed in any one of the preceding claims, wherein sorbitol is added to the mixture of filler material and liquid resol resin up to 1% by weight of said mixture.

10. A process as claimed in any one of the preceding claims, wherein the mixture placed in the mould includes a blowing agent.

11. A process as claimed in claims 1 and 10, comprising the steps of: (a) preparing a first mix of the following materials in the given proportions by weight; liquid resol phenolic resin 41 - 45% mineral fillers in powder form 50 - 53% hollow glass beads 3 - 6% (b) preparing a second mix of the following materials in the given proportions by weight; mineral fillers in powder form 48 - 52% hollow glass beads 4- 6% phenolic resin hardener 30 - 34% phenolic resin blowing agent 11 - 15% alpha modified phthalocyanine 0.08 - 0.4% (c) mixing together said first and second mixes in a weight ratio of 3:1, to obtain a homogenous mixture, (d) placing the resulting mixture in a mould so as partly to fill it and such that the ratio of the mould volume to the mixture volume produces a casting of the required final density, (e) mechanically agitating said mixture in said mould, (f) closing the mould and inserting it into the compartments of a multiple plate press, the plates of which are heated to a temperature of 75 - 90"C, (g) tightening the plates and keeping them tightened for 10 to 30 minutes, (h) removing the casting from the mould, and (i) curing the casting for 3 to 30 hours at 40 - 50"C.

12. A process as claimed in claim 1, wherein the mineral fillers are constituted by silica or any other quartziferous mineral in powder form.

13. A process as claimed in claim 11 or 12, wherein the blowing agent is a liquid fluorinated hydrocarbon.

14. A process for preparing a cellular, heat insulating, fire resisting, construction member substantially as hereinbefore described with reference to the examples.

15. A member prepared by a process as claimed in any one of the preceding claims.

16. A member prepared by a process as claimed in claim 1, 2, 3 or 4, comprising from 25 to 99% by weight of a heat hardened resol phenolic type resin, 1 to 6% by weight of hardener, and the balance being the filler material.

17. A member as claimed in claim 16, comprising iron inserts coated with epoxy paint.

18. A member prepared by a process as claimed in claim 1, 2, 3 or 4, comprising 20 35% by weight of resol phenolic resin: 70 - 50% by weight of mineral filler; 3 - 9% by weight of hollow glass beads; 5 - 8% by weight of hardener; 2 - 4% by weight of blowing agent and 0.02 - 0.1% by weight of alpha modified phthalocyanine.